The multipurpose gymnastic apparatus of the prior art is mainly composed of a frame unit, a pulley unit, and a load carrying device. An arm building device is pivoted to the front end of an upper beam of a ladder frame of the frame unit while a chair unit is set up at the center of the upper beam. A leg-stretching device is pivoted to the front end of the chair unit. Located behind the ladder frame is a chest building device under which another chair unit is mounted. The pulley unit is mounted at the upper and the bottom portions of the frame unit. The load carrying device is disposed by the frame unit and can be raised by a rope running on the pulley unit.
The prior art multipurpose gymnastic apparatus described above has a body of great size and weight and therefore takes up two much of the space. With a view to overcoming the shortcomings of the prior art multipurpose gymnastic apparatus described above, there are recently new multipurpose gymnastic apparatus that are disclosed in the Taiwanese Patent Numbers 79214330 and 80206840. The apparatus disclosed in the Taiwanese Patent 79214330 is characterized in that its arm building device can be easily converted into a chest building device by unfastening the two bolts so as to keep the baffle and the lifting-pressing bar apart. The apparatus disclosed in the Taiwanese Patent 80206840 has a feature that its arm building device is converted into a chest building device by unfastening the elongate bolt out of the slot of the baffle. As a result, the overall size of the multipurpose gymnastic apparatus of the above-identified patents is effectively reduced. However, such improved multipurpose gymnastic apparatus as described above are still limited in that the conversion of the arm building device into the chest building device can not be done quickly and easily by the user.